Nora
and Ben’s younger sister Birdy loves to keep secrets. She surprises her family
more than once: She hides a kitten in her room. She writes a beautiful poem.
One day Birdy watches her mother spit into a tube, ready to send it off to find
out more about herself and where her family came from. Birdy spits into a tube,
too, when no one sees her.

But
when the test results come back, they are a surprise. Birdy is seemingly not
related to Nora and Ben’s parents. But if she is adopted, how could that have
happened without the children knowing?

Nora
and Ben must learn when to keep a secret, and who to go to for help—and
eventually, how to solve this secret for the entire family.